They discover not far beneath the lunar surface a large slab—a monolith of perfect dimensions, 1:4:9—the squares of the first three integers: 12:22:32. When the monolith is exposed—a sign that life on the planet below has reached some level of ability and sophistication—its first encounter with sunrise causes a piercing beam of radio energy to be blasted across the solar system. The plot of each work, novel and film, involves a human expedition to the target of said radio beam.
Here, however, the stories diverge. In the novel, the signal is aimed at a moon in the Saturnian system. To the extent that the spaceship of exploration, Discovery One, flies to Jupiter at all, it is only briefly—a single chapter in which the crew uses the planet’s gravity as a slingshot to speed them along to Saturn. It is a harrowing episode, but Clarke’s imagination outpaced the abilities of special effects artists of the era. No one could create a Saturn that Kubrick found convincing, so rather than render a set of third-rate rings, the perfectionist filmmaker simplified the story. The monolith’s signal stopped now in the Jovian system, and all that followed did so in Jupiter’s orbit.41 The plots more or less converge there.
This small science-fiction factoid might have been consigned to the back of a Trivial Pursuit card were it not for the sequel, 2010: Odyssey Two, written by Clarke and published in 1981. Here the author faced a dilemma. Should he pen the story as a sequel to his novel, or to the film, which was released first and known more broadly? Did Dave Bowman, lone survivor of the computer HAL 9000’s psychotic break, abandon Discovery One in orbit around Saturn (at the moon Iapetus), or around Jupiter and one of its moons?
Clarke chose to write the novel as a sequel to the film. Odyssey Two opens with the Chinese spacecraft Tsien landing on Europa, its taikonauts trudging across the icy world on a reconnaissance mission for sources of water—a vital commodity if humans are ever to settle space. Before they can complete their task, however, some sort of evolved sea life emerges from a crack in the Europan ice shell, destroys the landing vessel, and slays every taikonaut but one, whose final, frantic message to Earth is: “. . . relay this information to Earth. Tsien destroyed three hours ago. I’m only survivor. Using my suit radio—no idea if it has enough range, but it’s the only chance. Please listen carefully. THERE IS LIFE ON EUROPA. I repeat: THERE IS LIFE ON EUROPA.”42
The novel ends with a mysterious message to Earth from an unknown celestial entity:
ALL THESE WORLDS ARE YOURS—EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE.
THE PROSAIC PRESENT remains squidless. Planetary science is a plucky upstart as far as scientific disciplines go, belonging once exclusively to the field of physics, and then to astronomy, and, since the start of space exploration, to geology. (As spacecraft and their scientific instrument payloads—the tools they carry that collect the data—evolve in sophistication, the fields of chemistry and biology will grow increasingly vital to the discipline.) To do geology, you need access to, or images of, hard surfaces. You need to see rocks and ridges and rubble and regolith. You can work backward. The snake looks like an ancient riverbed. Those stones, smoothed, get that way when water rubs rock. That’s a volcano, that’s a gorge, that’s a cliff. It’s easy on Earth because you can just look down and start studying, but before the rise of rockets, Mars existed only through telescopes, a smear of fire with ice caps on each end, and Venus was veiled in teal and impenetrable clouds.
It was the Apollo program that really made geologists tilt their heads upward in unison and ply their trade to untrodden worlds. Down in Alabama, Wernher von Braun, the exfiltrated German genius of rocketry, built the biggest booster ever to lift Luna-bound star voyagers. But nobody was sure, exactly, what the moon was made of or how hard its surface might be. What if we looked up each night to a lunar surface not of solid rock but of soft dust accumulated over billions of years and almost entirely undisturbed? What if the Eagle landed, and just . . . kept landing! Just sank right into the moon as though its surface were a powdery snowbank. While precursor robotic reconnaissance spacecraft had touched down on luna firma, would every part of the moon be like that? Oh, but it was even worse. What if the Eagle didn’t sink—what if astronauts set up Tranquility Base, walked around, planted the flag, and called the president, but when they climbed back into the lander, what if the moon dust was flammable? They’d pressurize the Eagle, and boom: Mare Tempestatis. NASA needed geologists to sharpen their pencils and solve the problem most ricky-tick—and to the great relief of Apollo astronauts, they did. The magnitude of the achievement of geologists to understand an orbiting ancient alabaster rock was reflected in the second thing Neil Armstrong said, after taking a giant leap for mankind:
“And the—the surface is fine and powdery. I can—I can pick it up loosely with my toe. It does adhere in fine layers like powdered charcoal to the sole and sides of my boots. I only go in a small fraction of an inch, maybe an eighth of an inch, but I can see the footprints of my boots and the treads in the fine, sandy particles.”43
And planetary science was off to the races.
Bob Pappalardo entered that race in earnest twenty years after taking a desk in Carl Sagan’s classroom, with Jet Propulsion Laboratory beckoning him: Come to California. Set up a Europa laboratory. Help us build a proper program on Europa. Help find that life. You won’t get there from Colorado, Bob. Are you interested?
Yes, Bob said. I am interested.
Seventeen months of negotiations followed. They weren’t tense, exactly, but they were tedious: title, lab facilities. He wanted a salary such that in Los Angeles, he could buy a house similar to the one he had in Lyons. That delayed things. I mean, what does a house in Colorado cost? How much? You’re not getting a house that size for that money in L.A.! You’re not getting a house that size in L.A. for double that price.44 So there was a firm but gentle and sometimes terse but generally respectful back-and-forth. Ultimately, the numbers fell in Bob’s favor, but there was one more thing he wanted.
During preliminary discussions, the lab teased the prospect of Bob being the project scientist of a Europa mission—its leader, in other words—should a mission go forward. This was so far outside the scope of the career Bob had imagined for himself that it veered into areas incomprehensible. Before the lab came calling, Assistant Professor Pappalardo’s goal—he’d written it down and everything in one of those what-do-you-want-out-of-life? workbooks you find in the self-help section of bookstores—was to be the lead scientist on a camera carried by some spacecraft that might one day return to Jupiter. He wasn’t even asking to be Spock; Gene Roddenberry would have listed him in the credits as Blue Shirt Crewman #3, maybe. It was still an enormously ambitious goal—any scientist’s crowning professional achievement. But to be project scientist? Look, one flagship launches every decade. And there’s only one person who gets to be project scientist. It would be far easier, statistically, to be an astronaut—NASA employed about a hundred of those, versus maybe five or so project scientists to launch a flagship mission to the outer solar system, and not “at the time,” but ever. Part of it was because the outer planets were so aptly named—Jupiter (the nearest outer planet) was one wire past Mars on the classroom solar-system-around-the-yellow-lightbulb model, but took vastly longer to reach. Pregnancies lasted longer than a trip to Mars, but by the time a spacecraft reached Jupiter, the same child would not only be born, but would be old enough to play on a youth soccer team.
Which made Mars an enticing object of exploration—more so, even, because every robotic Mars mission could be framed as a precursor for human exploration. And though astronauts hadn’t touched a celestial object beyond Earth since the last Apollo flight in 1972, NASA was thoroughly and indelibly an astronaut-led, astronaut-centric organization, and Mars its elusive but inevitable target post-Apollo.
Programmatically, the Red Planet was an enterprise unto itself at the agency and competed against only itself for flight projects. Every twenty-six months, as orbits aligned, something would launch for Mars. For every ot
her object in outer space, however, it was urban warfare. Headquarters was, on a good day, apathetic to aspirations for an outer planets flagship (the outer planets as in all of them, and their hundreds of moons of fire, ice, rock, and metal) and, ordinarily, entirely antipathetic if not actively antithetical. As a result, the outer planets competed against not only themselves as worlds worthy of exploration (e.g., Do we go next to Io or Iapetus?), but also against every other object in the solar system. You wanted a flagship to Neptune, you had best be better than Venus. You wanted a Triton orbiter, and you’re crossing swords with Mercury, Ceres, or Saturn. NASA selects a spacecraft to study an asteroid or comet, and it is never Mars that will want for hardware on the launch pad; it’s Europa or Titan or even the moon. And if you were a non-Mars researcher, you couldn’t help but feel some irritation? annoyance? envy? Look, the Mars community labored mightily for its success, and if you studied the outer planets or Venus or the giant asteroid Vesta, you probably, in fact, worked on one Mars mission or another, or did research on Mars data, because the grant money was there and your car payment was due next week. Despite an unbroken chain of NASA budget squeezes and shortfalls going back to the end of Apollo, everyone needed Mars to prosper because it was like social security for solar system scientists. The government might meddle, but it would never kill it. Places like NOT MARS, however, were always maybes, always if-we-can-afford-its.
Then again, you never knew. And if some sympathetic functionary at NASA headquarters got traction and convinced the right person to give Europa a chance, Bob wanted it in writing that he would be the project scientist of that mission.45 JPL management personnel didn’t say no, but they couldn’t say yes on paper. They could, however, formally declare that he would be their top candidate for project scientist should a mission go forward. It was a sign, at least, that they were serious, and Bob signed on the dotted line. Three years, he figured, and NASA would want his mission. As the lone survivor of the Tsien could attest, however, Europa would not prove so hospitable to callers.
In the end, it would take seventeen years, six major studies, multiple missions approved, multiple missions abandoned, friendships formed and enmities established, funding raised and budgets lost, congressional hearings, unlikely alliances, technological breakthroughs, terrible losses, and stunning discoveries to get NASA to make it official.46
But much of that was yet to come. A contract signed, Bob Pappalardo packed his life and his cat and pointed his car westerly—one more northeasterner with his sights set on Pasadena. He had once missed a total solar eclipse, but that was OK. They could have the sun. In 2006 the child of Trek was California bound. This time, he was after a moon.
Chapter 2
Situations Vacant
LOUISE PROCKTER FINISHED THE EMAIL AND SENT IT. Just like that. One sentence and a CV attachment, and it was out there now, three branches down the tree of life that sustained the American space program: Drafts to Outbox to Sent Items. She opened her planner to December 21, 2006, pressed pen to page (blue ink for Europa’s turbulent ocean, currents coursing fathoms below), and crossed it from her list of things to do that day. Volunteer for new Europa mission study. Done. From her little office at the Applied Physics Laboratory of Johns Hopkins University in Maryland, Louise worked full-time on the MESSENGER mission to Mercury, part of the spacecraft’s camera team. Her role on the project kept page after page and line after line full in her color-coded Levenger planner (Mercury in red for its intense heat), but she would fill the margins with blue ink, if necessary. I mean, this was Europa. She belonged on that study.
And why not? She’d paid her dues on the late JIMO’s science definition team, where she co-led the geology and geochemistry group. She’d planned observation orbits of the spacecraft Galileo around Jupiter before that. (Poor radiation-poisoned Galileo, asleep at last.) She’d published a steady stream of papers on icy moons, and Europa in particular. She knew more about dark terrain on Ganymede than probably anyone else in the world and had written the dark terrain section for Fran Bagenal’s book on Jupiter. The last twelve months alone, working on MESSENGER—a tortured but accurate acronym for the Mercury Surface, Space Environment, Geochemistry, and Ranging mission—had proved among the most exhilarating of Louise’s life—and that spacecraft had another four years to go before entering orbit around the planet nearest to the sun.
Space exploration was not for the impatient. It took years to get a mission approved by NASA, years further to get it built and off the ground, and except for Mars (with its favorable celestial alignments with Earth), still more years yet for it to reach its destination. In the case of MESSENGER, rather than flying directly to Mercury, which would have been faster but bananas in its fuel requirements, like most spacecraft in NASA’s fleet, it would instead pinball around the solar system using slingshot maneuvers called “gravity assists,” swinging by this planet or that and leveraging the encountered planet’s massive well of gravity and atmospheric friction to speed up, slow down, or make major trajectory changes. This allowed the vessel to carry less fuel at launch, which in turn meant NASA could use a smaller rocket to launch it from Earth, saving tens of millions of dollars.
MESSENGER’s mission plan called for the spacecraft to lift off and oval the sun until it again met Earth for a course correction that would kick it inward to Venus and again around the sun for another, more harrowing Venusian encounter (a terrifyingly low two hundred ten miles above its surface), really reducing the vehicle’s velocity now and angling it inward toward Mercury, circling the sun another dozen times, thrice buzzing the tiniest inner planet, easing, easing, easing ever so slightly into formation with Mercury, until finally, finally, finally the spacecraft might slide gingerly into the tiny planet’s ethereal orbit. The distance from Earth to Mercury at their closest was about fifty million miles. The distance MESSENGER would travel ultimately from launch to arrival: nearly five billion miles.47
So far, the vehicle had had its gravity assists from Earth and Venus. For much of the duration of these “cruise phase” operations, MESSENGER’s science payload remained active, each instrument team working full-time, including Louise and the rest of the camera crew. During the Earth encounter, the spacecraft captured two of the most stunning shots of our azure orb that she had ever seen. There it was: South America, with Africa wrapped along the lower crest of Earth like some great giant’s gentle hand holding up the world for inspection.48 And while flying away, a parting image of the Galápagos Islands gilded with a glint of sunlight.
None of this just happened, of course: the images of Earth, the orbital adjustments, the golden glint of sun. (Well, that one just happened.) It had to be planned, all of it, and rigidly, every image, every video, every second of every sequence, taken by a spacecraft speeding six and a half miles for each of those seconds, the laws of physics alone keeping the spacecraft in precisely the right place at precisely the right time. The whole point of the exercise (beyond bagging opportunistic new photos of our home planet) was to work out the wrinkles before you got to Mercury: team dynamics, mechanical calibrations, image sequence plans, camera control software development. All of it was critical to ensuring that the prime mission at Mercury moved from day one as if on rails. The work did not stop during the years-long cruise phase, and it could be spellbinding, tedious, challenging, or all three of those at once, but even with its decadal timescales, there was an urgency inherent to space exploration that energized everyone, and especially Louise, who simply could not believe that this was her life, but who never stopped to think too hard about it because there was so much work yet to be done. Earth, Venus, Venus, Mercury, Mercury, Mercury, orbital insertion—you never punched out early. And the excitement of it all, you internalized it. It became you. And eight weeks after the first flyby of Venus, one year after seeing the sun-kissed Galápagos Islands,49 you’re writing a one-sentence email to Curt Niebur at NASA headquarters, CV attached, and you’re telling the guy trying to get a Europa mission going, Hi, Curt,
I would like to submit my application for membership of the SDT for the new Europa flagship study, and you add in parentheses—because, let’s face it, who in the community wouldn’t want to be on the study, and you are one hell of a Europa scientist but nothing is ever a sure thing—or the Ganymede study—I believe I could also make a useful contribution to that study, which you could, and, you add, again, because, look, you really are one of the best qualified Europa scholars out there, but I think I could make a greater contribution to the Europa study.50
And just like that, you send it and see how far you can ride this thing: in ten years, Louise had gone from undergrad to section supervisor of the Planetary Exploration Group at the Applied Physics Laboratory. So why not send that email? I mean, we were talking about Europa here. If there was a chance—any at all—of going back, she had to be part of it.
BEFORE SHE FLEW spacecraft for a living, Louise Prockter sold newspaper advertisements. To her parents’ shock and horror, she announced at seventeen that she was absolutely not going to university, and that was that—settled, over—and she found a job at a local paper in London, where she addressed envelopes and made tea for her bosses. It was 1982. The move to sales was a big promotion. They placed her in charge of the paper’s sits vac, or situations vacant—want ads for companies hiring—and she was good at her job and she had an active social life and she was well on her way, sits vac by day and antics by night and aspirin by morning. She wasn’t, she recognized at the time, a particularly good person, but rather, just a person, a Londoner, and she ran with a certain crowd, and she was muddling through, making her way. It was life.
The Mission Page 4